This document compares four series of Cisco network processors: VXR 7200, SBC 7600, ISR 4451-X, and 7606. It summarizes the key features of each series, including their intended uses, processing power, speeds, supported services and protocols. A table compares the four series across features such as scalability, flexibility, security capabilities, processing power, speeds, and supported services. The document concludes that Cisco network processors provide high performance routing and switching solutions for various applications.